Magnesium sulfate, a drug given to mothers at risk of preterm delivery in an attempt to delay the birth, can help their babies from developing cerebral palsy, or CP, a disorder which affects movement, motor skills and muscle coordination, causing brain damage during birth.

The findings detailed in the New England Journal of Medicine suggest that giving expectant mothers an infusion of magnesium sulfat, also known as Epsom salt, in the days before the delivery can cut their child risk of developing cerebral palsy by about a half.

The study involved more than 2,200 pregnant women who were at high risk for premature birth – between 24 and 31 weeks. Half of them were given magnesium sulfate before the delivery and the other half was given a placebo infusion. At the end of the study, researchers found that moderate or severe palsy occurred in just 1.9 percent of the group treated with magnesium sulfate, compared to 3.5 percent in the placebo group. There was no significant difference in the proportion of deaths between the two groups.

The disorder affects the child’s ability to control movement and it is caused by damage to or dysfunction of the developing fetal or infant brain. For premature babies, the cerebral palsy rate is 20 to 50 in 1,000, compared to one in 1,000 in the case of full-term babies.

Study lead author Dr. Dwight J. Rouse, a professor of obstetrics and gynecology at the University of Alabama at Birmingham, said the compound may “stabilize the vessels in the vulnerable preterm brain” and may protect the brain from damages caused by lack of oxygen.

The study is published in the Aug. 28 issue of the New England Journal of Medicine.

Researchers said the findings are applicable only to early preterm birth. The practise should be strongly considered for women at risk of delivering before 32 weeks.